Gas developing machine for photosensitive sheets



Oct. 27, 1959 GAS DEVELOPING Filed Jan. 11, 1955 F. G. WILDE 2,909,980 MACHINE FOR PHOTOSENSITIVE SHEETS 3 Sheets-Sheet 1 INVENTOR. FREDERICK 6. W/LDE ATTORNEY F. G. WILDE Oct. 27, 1959 GAS DEVELOPING MACHINE FOR PHOTOSENSITIVE SHEETS 3 Sheets-Sheet 2 Filed Jan.

- INVENTOR.

FREDERICK a was ATTORNEY Oct. 27, 1959 F. e. WILDE 2,909,980

GAS DEVELOPING MACHINE FOR PHOTOSENSITIVE SHEETS Filed Jan. 11, 1955 3 Sheets-Sheet 3 4 TTORNEY XL United States Patent GAS DEVELOPING MACHINE FOR PHOTOSENSITIVE SHEETS Frederick G. Wilde, Rochester, N.Y., assignor to Paragon- Revolute Corporation, Rochester, N.Y., a corporation of New York Application January '11, 1955, Serial No. 481,107

3 Claims. (Cl. 95-94) The present invention relates to machines for developing photosensitive sheets by means of ammonia gasand the like. The machine of the present invention constitutes an improvement upon the machine illustrated in the U.S. patent to Sullivan et al., No. 2,475,809, granted July 12, 1949.

In conventional developing machines of this type, ammonia gas is generated in a chamber or tank which is open at its rear and which is closed by means of an impervious endless belt that rides over two cylindrical guides, that are secured to the tank at the upper and lower ends, respectively, thereof, and over a plurality of rollers that are journaled in the tank between the two cylindrical guides. The photosensitive sheet to be processed is drawn over the guides and rollers by means of the impervious belt. The ammonia gas reaches the sheet through the spaces between the rollers and through perforations in the rollers themselves, but is prevented from escaping from the tank by the impervious belt which overlaps the rollers and the guides, at both sides laterally and at both ends.

It has been found in practice that, despite the fact that the cylindrical guides are made of smooth, tubular metal stock, there is a tendency for the photosensitive paper to stick to these guides and to buckle, sometimes, as a result, feeding into the tank instead of over the rollers and guides. It has been the practice in some cases, therefore, to mount guide rods in recesses on the rollers to insure that the photosensitive sheet will follow its intended path along the undersurface of the belt and not be diverted between the rollers into the tank.

The primary object of the present invention is to provide an improved machine for developing photosensitive sheets by means of ammonia \gas and the like in which all friction between the photosensitive sheet, which is to be processed, and the members over which it travels in its passage over the tank, is eliminated. To this end it is an object of the invention to provide a machine of the character described in which rotary, cylindrical sealing tubes replace the cylindrical guides previously used.

Another object of the invention is to provide a machine of the character described in which at least one of the cylindrical sealing tubes is positively driven, further to assure travel of the photosensitive sheet in its intended path without being diverted between the rollers into the tank.

Another object of the invention is to provide a machine of the character described in which the sealing tubes, tank, and other parts, such as the rollers, which become heated up in operation, are free to expand laterally without affecting the operation of the machine.

Other objects of the invention will be apparent hereinafter from the specification and from the recital of the appended claims.

In the drawings:

Fig. l is a vertical section through a machine built according to one embodiment of the present invention,

Patented Oct. 27, 1959 the section being taken approximately on the line 11 of Fig. 2, and looking in the direction of the arrows;

Fig. 2 is a rear elevation, with parts broken away and shown in section, of the tank, showing the mountings for the rollers and sealing tubes;

Fig. 3 is a fragmentary view showing the upper sealing tube fragmentarily, and details of the seal therefor;

Fig. 4 is a section on a line 4-4 of Fig. 2 looking in the direction of the arrows; and

Fig. 5 is a section on the line 55 of Fig. 2 on a much reduced scale and looking in the direction of the arrows and showing the manner of mounting the tank.

Referring now to the drawings by numerals of reference, the developing machine of the present invention is provided with a base 10 adapted to be mounted upon a table. On this base there are mounted two spaced end frames 11, suitably held in spaced relation to form part of a cabinet. The rear of this cabinet as well as the top and upper portions of the front of the cabinet are closed by a cover which also serves as a hood to collect waste fumes. This cover is denoted generally at 12. It may be made in a plurality of sections (not shown) hinged together according to conventional practice.

The developing tank comprises a sheet metal structure designated generally at 15 which is substantially troughshaped in cross-section, as shown in Fig. l. The opposite sides of this developing chamber or tank are denoted at 16 and 17, respectively. Welded or otherwise secured to the sides of the tank at the lower left hand edge of the trough, as shown in Fig. 2, are two bearing members 20,

which have pins 21 protruding therefrom inwardly toward one another. These serve as mounts for roller bearings 22 on which are journaled end plugs 24 which have a press-fit into opposite ends of a rotary, cylindrical sealing tube 25. This sealing tube 25 is somewhat shorter in length than the distance between the bearing members '20 so that some space is provided for longitudinal expansion of the tube.

Secured at the upper end of the tank to the side wall 16 thereof as by a screw 30 (Fig. l) is a bearing mem- -ber 31. The bearing member 31 is formed with a protrusion or stud 34 which serves to support a ball bearing 35 on which an end plug 36 that has a press-fit in one end of a sealing tube 38, is mounted. This sealing tube is secured at its opposite end by means of a set-screw 39' to an end plug 40 and to a shaft 42. Shaft 42 is journaled on spaced bearings 44 in a bearing member 45. Bearing member 45 is secured by screws 47 to the side wall 17 of the tank.

End plug 40 is formed at its outer end with a truncated conical protrusion 46 which is received within a recess in bearing member 45. The sealing tube 38 is made of a length to have clearance at its left hand end with reference to the bearing member 31; and the end plug 40 is made so that there is greater clearance for expansion between the end face 48 of the end plug 40 and the opposed,

adjacent face 49 of the bearing member 45 than between the end of the protrusion 46 and the adjacent bearing 44, so that if there is undue expansion this will be taken first by the bearing 44, avoiding friction between the abutting faces of the end plug and the bearing member 45.

Between the sealing tubes 25 and 38 there are mounted a plurality of parallel, cylindrical rollers 55 which are arranged in a steeply inclined row. These rollers comprise cylindrical tubes 56 in which the end plugs 57 at opposite ends have press-fits. End plugs 57 are mounted on pins 58 which have protruding portions 60 journaled in cups 62 that are welded or otherwise secured to the side plates 16 and 17 of the tank. The tubes 56 of the rollers 55 are made of perforated sheet metal such as stainless steel; and the perforations permit maximum access of the developing gas to the photosensitive sheet which is to be developed. The cups 62 are long enough axially to permit endwise expansion of rollers 55 without binding.

The open side of the tank, in which the sealing tubes 38 and 25 are mounted, is closed by the impervious belt 65 which travels over the sealing tubes 25 and 38 and the intermediate rollers 55, and which passes around the driven roll 66 at the lower end of the machine and the guide roll 67 in the upper part of the machine. This belt is made in conventional manner of rubber or other flexible material impervious to ammonia or other developing gas. It is wide enough so that its edges engage parts of the side walls of the tank or chamber to provide an effective seal and to prevent leakage of gas from the developing chamber. The rollers 55 and the sealing tubes 25 and 38 form a support for the belt.

The rollers 55 are spaced apart sufficiently to allow the processing gas to have access to the photosensitive sheet as it travels over the rollers under actuation of the belt 65. The spacing between adjacent rollers is, however, preferably less than the diameters of the rollers so that the front end of the photosensitive sheet will have to follow along with the belt 65. In order, however, to prevent the photosensitive sheet from falling into the tank, a grid 70 may be provided under the rollers 55 and close thereto. This grid may consist simply of a plurality of parallel Wire rods. It may be supported by brackets 71 and 72 at the upper and lower ends thereof.

In order to prevent leakage of gas from the tank around the sealing rollers 25 and 38, rubber or neoprene seals may be provided.

For sealing around the lower sealing tube 25 two flexible natural, or artificial rubber pads 26 are provided at the inside of the tube adjacent opposite side walls of the tank, respectively, to engage the periphery of sealing tube 25. These pads are secured to the inside of the tank by bolts 27, and each is wide enough to extend over the gap between a bearing member 20 and the adjacent end of the sealing tube. In addition, at the outside of the tube there are provided a plurality of flexible rubber strips 80 (Fig. 4) which extend along the full length of the tube and which are secured at opposite ends to the tank by the bolts 27. A spacer bar 83 is interposed between strips 80 and tank 15 to hold the strips 80 in proper position. Bolts 27 secure this spacer bar in position also. The strips 80 are of successively greater widths from inside to outside so that together they closely conform to the cylindrical contour of the sealing tube 25 as shown in Fig. 4 so as to provide a tight seal thereagainst. The strips 80 extend over the full length of the bearing members 20 and the sealing tube 25. In addition there are provided flexible rubber sealing strips 82 adjacent opposite sides of the tank which extend over strips 80 and overlap the bearing members 20 and the adjacent ends of the sealing tube 25, sealing the spaces between the tube and the bearing members. These strips are held in place also by the bolts 27. They are held against the peripheries of the bearing members 20 and tube 25 by metal spring clips 84 which are provided adjacent opposite ends of the tank, and which are secured in position by the bolts 27.

The sealing tube 38 is sealed in a similarmanner. Secured to each of the bearing members 31 and 45 by screws 34 are rubber pads 33 which extend across the gaps between the bearing members and the adjacent ends of the sealing tube 38. These pads extend over, that is above tube 38, part way around the periphery of the tube 38 in engagement therewith. Mounted on the top of the tank, also, are a plurality of rubber'strips 90. These extend for the full width of the tank overlapping the sealing tube 38 and the bearing members 31 and 45. These strips 90 are of successively greater width from bottom to top so that their engaging ends conform together to the cylindrical shape of the tube 38 and engage the tube closely. They are held in position by a metal plate 91 and screws 92. The upper wall of the tank is denoted at 95.

The several rollers 55 and the sealing tubes 25 and 38 may all be driven by frictional engagement with the impervious belt 65. However, it is preferable to drive the upper sealing tube 38, at least, and preferably at a speed slightly greater than the speed of the belt. The drive to the tube 38 may be achieved by extension of the shaft 42 (Fig. 2). The shaft 42 is mounted for this purpose on ball bearings 102 and has a driven sprocket secured thereto. Bearings 102 are mounted in the tubular portion 103 of a yoke member 105 (Figs. 2 and 5). Sprocket 100 may be driven in time with the other driven members of the machine, such as roller 66, and from the same source of power.

To permit the tank to expand and contract, the tank is mounted so as to float freely in the frame of the machine. This floating tank mounting is achieved, in part, through the yoke member 105. Yoke member 105 is secured to one side 11 of the machine by screws 108. Its bearing portion 103 floats freely in a hole 109 (Fig. 2) in said one side 11. It also has a bearing portion 110 which floats freely in a hole 112 in said one side 11. Bearing member 110 has a stud or pin 106 threaded in it which has sliding bearing engagement in the bearing cap '20 at the right hand side (as viewed in Fig. 2) of the tank. Studs or pins 37 that thread into the other side 11 of the machine frame and that have sliding bearing engagement with the bearing member 31 for upper sealing tube 38 and with the bearing member 20 for the left hand side (as viewed in Fig. 2) of the lower sealing tube 25, respectively, floatingly support the tank at its opposite side. The tank 15 is, therefore, free to float laterally in the frame of the machine. Hence, the contact of sealing tubes 25 and 38 with the rubber strips can be maintained without undue friction.

The photosensitive sheet is introduced between the belt 65 and the cylindrical sealing tube-25 at the lower part of the cabinet, being directed to this point by a conventional guide plate (not shown). The photosensitive sheet is moved upwardly by the belt 65 over the rollers 55, being exposed at this time to the processing gas which has access to the sheet through the perforations in the rollers and through the spaces between the rollers. The process sheet emerges from between the belt 65 and the upper sealing tube 38 to drop into a conventional receptacle.

While the invention has been described in connection with a particular embodiment thereof, it will be understood that it is capable of further modification, and this application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles. of the invention and including such departures from the present disclosure as come within known or customary practice in the art to which the invention pertains, and as fall within the scope of the invention or the limits of the appended claims.

Having thus described my invention, what I claim is:

1. In a developing machine, a chamber adapted to contain gas, said chamber having an exposure area at one side thereof through which a photosensitive sheet can be exposed to said gas, a pair of bearing members fixedly secured in axially spaced relation to said chamber at both the upper end and at the lower end of said exposure area, a sealing tube journaled between each pair of bearing members, said sealing tubes extending in parallelism along the upper and the lower boundaries, respectively, of said exposure area and being spaced axially slightly from the cooperating bearing members to provide gaps at each end of each sealing tube to permit expansion of said sealing tubes, means for sealing against leakage of the gas from said chamber between said sealing tubes and the adjacent portions of said chamber, said sealing means comprising flexible pads fixed relative to said chamber and which ex tend across said gaps and overlap portions of said sealing tubes and "the adjacent bearing members and which extend part-Way around the peripheries of said sealing tubes, and a plurality of flexible flat strips of rubber-like material associated with each sealing tube which extend along the full length of the associated sealing tube and overlie the gaps at each end thereof and which contact the peripheries of the sealing tubes and which are secured in fixed relation to said chamber, said flexible strips being arranged so that their contacting portions are progressively advanced beyond one another in an arc conforming to the peripheral curvature of the associated sealing tube, a plurality of rollers mounted across said exposure area in spaced relation parallel to one another and parallel to said sealing tubes, and an impervious belt movable in a direction at right angles to the axes of said sealing tubes and rollers, said belt being disposed relative to said sealing tubes and rollers to cooperate therewith to advance the photosensitive sheet past said exposure area upon movement of said belt, said belt being in contact with the lateral side edges of said chamber at said exposure area to close and seal the same, and means for advancing said belt across said area.

2. In a developing machine, a frame, a tank adapted to contain a gas, means for mounting said tank in said frame so that said tank is free to float laterally in said frame upon expansion and contraction, said tank having an exposure area at one side thereof through which a photosensitive sheet can be exposed to said gas, a pair of bearing members fixedly secured in axially spaced rela tion to said tank at both the upper end and at the lower end of said exposure area, a sealing tube journaled in each pair of bearing members to be slightly spaced axially from the adjacent bearing member to provide gaps at each end of the bearing member for axial expansion and contraction, said sealing tubes extending, respectively, along the upper and lower boundaries of said exposure area, means for sealing against leakage of the gas from the tank through said gaps, means for sealing against leakage of the gas from said tank between each sealing tube and the adjacent boundary of said tank, a plurality of rollers rotatably mounted at opposite ends, respectively, in said tank to extend across said exposure area, said rollers being spaced from one another and disposed parallel to one another and to said sealing tubes, and an impervious belt movable in a direction at right angles to the axes of said sealing tubes and of said rollers, said belt being disposed relative to said sealing tubes and rollers to cooperate therewith to advance the photosensitive sheet past said exposure area upon movement of said belt, said belt being in contact with the lateral edges of said tank at said exposure area to close and seal the same, said means for mounting said tank in said frame comprising supporting members slidably connecting said frame to both of the bearing members for each sealing tube to permit relative expansion between each sealing tube and the frame, one of the supporting members for one of the sealing tubes being a shaft which extends axially through one bearing member for said one tube and to which said one tube is secured, means for advancing said belt across said exposure area, and means for driving said shaft to drive said one sealing tube independently of said belt.

3. In a developing machine, a frame, a tank adapted to contain a gas, means for mounting said tank in said frame so that said tank is free to float laterally in said frame upon expansion and contraction, said tank having an exposure area at one side thereof through which a photosensitive sheet can be exposed to said gas, a pair of bearing members fixedly secured in axially spaced relation to said tank at both the upper end and at the lower end of said exposure area, a sealing tube journaled in each pair of bearing members to be slightly spaced axially from the adjacent bearing member to provide a gap at each end of each sealing tube for axial expansion and contraction, said sealing tubes being parallel to one another and extending, respectively, along the upper and lower boundaries of said exposure area, means for sealing against leakage of the gas from the tank through said gaps, means for sealing against leakage of the gas from said tank between each sealing tube and the adjacent boundary of said tank, a plurality of rollers rotatably mounted at opposite ends, respectively, in said tank to extend across said exposure area, said rollers being spaced from one another and from said sealing tubes and being disposed parallel to one another and to said sealing tubes, and an impervious belt movable in a direction at right angles to the axes of said sealing tubes and of said rollers, said belt being disposed relative to said sealing tubes and rollers to cooperate therewith to advance the photosensitive sheet past said exposure area upon movement of said belt, said belt being in contact with the lateral edges of said tank at said exposure area to close and seal the same, said means for mounting said tank in said frame comprising a yoke secured to said frame, members connecting said yoke to one of the bearing members for each sealing tube to permit relative expansion between each tube and the yoke, one of the connecting members for one of said sealing tubes comprising a shaft which extends axially through the one bearing member for said one tube and to which said one tube is secured, and members slidingly connecting said frame with the other bearing members for the two tubes, means for advancing said belt across said exposure area, and means for driving said shaft to drive said one sealing tube independently of said belt.

References Cited in the file of this patent UNITED STATES PATENTS 1,277,202 Dye Aug. 27, 1918 2,009,962 Kurten July 30, 1935 2,299,045 Trump Oct. 13, 1942 2,475,809 Sullivan et a1 July 12, 1949 2,515,144 Trump et al July 11, 1950 FOREIGN PATENTS 852,807 Germany Oct. 20, 1952 

